The AP Third-Team All-American was one of four players to leave the Terps via the transfer portal on Tuesday.
The Terps lost their first meeting with the Buckeyes, but with the Big Ten tournament looming they found a crucial win.
"Every single person can score the basketball," coach Brenda Frese said. "It's just you guys are used to the faces that scored it for us last year."
Charles, once expected to be a first round pick, slid to deep in the second last Friday.
Mikesell earned All-Big Ten honors in both her seasons with the Terps.
Guard Ashley Owusu led the way with 17 points, six rebounds and 11 assists.
Taylor Mikesell led the way with six triples as part of her 22 points.
"We’re playing for our seniors. ... We want to make sure we send them out the right way."
Forward Kaila Charles was named to the first team, and guard Blair Watson was named to the All-Defensive team.
It's the Terps' fifth Big Ten regular-season title in the last six years.